Last Updated or created 2024-08-04

Last week I bought an old Bornhack Badge. I thought it needed a display.

Using a SSD1306 display, and Circuitpython I made this.

( Wooded thingy contains an RFID chip ( Part of my player ))

Library and files needed:

• font5x8.bin in root of filesystem ( just google for this file )
• copy of adafruit_framebuf.mpy in /lib
• copy of adafruit_ssd1306.mpy in /lib

Code: (midway some pixel examples, just uncomment)

import board
from time import sleep
import busio 
from PN7150 import PN7150
import adafruit_ssd1306
import math
import adafruit_framebuf


if True:
    # Fast 400KHz I2C
    i2c = busio.I2C(board.SCL, board.SDA, frequency = 400000)
else:
    # Regular 100kHz I2C
    i2c = board.I2C()


WIDTH = 32
HEIGHT = 8

buffer = bytearray(round(WIDTH * math.ceil(HEIGHT / 8)))
fb = adafruit_framebuf.FrameBuffer(
    buffer, WIDTH, HEIGHT, buf_format=adafruit_framebuf.MVLSB
)


nfc = PN7150(i2c, board.IRQ, board.VEN)

display = adafruit_ssd1306.SSD1306_I2C(128, 32, i2c,addr=0x3c)

assert nfc.connect()
print("Connected.")

assert nfc.modeRW()
print("Switched to read/write mode.")

display.fill(0)

display.show()

#display.fill(0)
#display.text('Hello', 0, 0, 1 )
#display.text('World', 0, 10, 1)
#display.show()
# Set a pixel in the origin 0,0 position.
#display.pixel(0, 0, 1)
# Set a pixel in the middle 64, 16 position.
#display.pixel(64, 16, 1)
# Set a pixel in the opposite 127, 31 position.
#display.pixel(127, 31, 1)
#display.show()

while True:
    display.fill(0)
    display.text('Waiting for card', 0, 0, 1 )
    display.show()

    assert nfc.startDiscoveryRW()

    print("Waiting for card..")
    card = nfc.waitForCard()
    assert nfc.stopDiscovery()

    print("ID: {}".format(card.nfcid1()))
    id = card.nfcid1()
    display.text(id, 0, 10, 1 )
    display.show()

    sleep(0.5)

Not sure about display i2c address? Use below code

import time
import board
import busio

# List of potential I2C busses
ALL_I2C = ("board.I2C()",)

# Determine which busses are valid
found_i2c = []
for name in ALL_I2C:
    try:
        print("Checking {}...".format(name), end="")
        bus = eval(name)
        bus.unlock()
        found_i2c.append((name, bus))
        print("ADDED.")
    except Exception as e:
        print("SKIPPED:", e)

# Scan valid busses
if len(found_i2c):
    print("-" * 40)
    print("I2C SCAN")
    print("-" * 40)
    while True:
        for bus_info in found_i2c:
            name = bus_info[0]
            bus = bus_info[1]

            while not bus.try_lock():
                pass

            print(
                name,
                "addresses found:",
                [hex(device_address) for device_address in bus.scan()],
            )

            bus.unlock()

        time.sleep(2)
else:
    print("No valid I2C bus found.")